Course Hero BIO Organisimal

BIO 1131 L AB E XERCISE 1 W ORKSHEET : F INCH N ATURAL S ELECTION D ATA A NALYSIS N AME : S ARAH CHILD Part A: Analyzing Graphical Data 1. In Figure 1 (on page 2 of your Lab Manual) there are two histograms shown. What is the variable that is measured in these histograms? Beak Depth 2. What was the mean and range of the data for birds in the left histogram? The mean was 9.11 mm and the range was 7.5 mm to 11.25 mm 3. What was the mean and range of the data for birds in the right histogram? The mean was 9.67 mm and the range was 8 mm to 11.25 mm 4. What can you conclude by comparing the two histograms? By comparing these histograms I can conclude that one factor that allowed the survivors to survive was a larger beak depth. 5. Propose a biologically-based research hypothesis to explain the differences in the distributions of the variable measured on the birds that survived vs. those that did not survive the drought of 1977. The birds that survived the drought of 1977 had certain traits that helped them cope with the harsh conditions. One possible trait is having a larger beak depth. This could have given them a survival advantage compared to birds that did not possess this characteristic. 1

BIO 1131 L AB E XERCISE 1 W ORKSHEET : F INCH N ATURAL S ELECTION D ATA A NALYSIS N AME : S ARAH Part B: Descriptive Statistics 6. Fill out this data table based on the data you recorded on page 3 of the lab manual. You may copy and paste your table if preferred. Descriptive Statistics Nonsurvivors Survivors Body Mass (g) Wing Length (mm) Tarsus Length (mm) Beak Depth (mm) Body Mass (g) Wing Length (mm) Tarsus Length (mm) Beak Depth (mm) Mean () 15.7126 67.7886 19.0833 9.111 16.9942 69.2966 19.3472 9.6738 Variance (s 2 ) 1.842 5.181 0.701 0.775 3.087 5.448 0.735 0.709 Standard Deviation = 1.35715 6105 2.27626 7093 0.83709 32213 0.8801 258027 1.75706 8628 2.33410 1768 0.857578 5559 0.84223 92166 Standard Error of the Mean (SEM) 0.19193 0857 0.32191 27794 0.11838 28587 0.1244 685847 0.24848 70284 0.33009 18376 0.121279 9225 0.11911 06123 95% Confidence Interval 0.38386 1714 0.64382 55588 0.23676 57173 0.2489 371694 0.49697 40567 0.66018 36751 0.242559 8449 0.23822 12246 2

BIO 1131 L AB E XERCISE 1 W ORKSHEET : F INCH N ATURAL S ELECTION D ATA A NALYSIS N AME ARAH CHILD PART E: Examining the Importance of Sample Size 9. Enter the values here from page 6 (Table 3) in a table form here:. Mean Standard deviation 5-finch sample 15-finch sample 50-finch sample 5-finch sample 15-finch sample 50-finch sample Non-survivors 8.784 9.1133333 33 9.111 1.1527488 89 0.9831848 153 0.8801258 027 Survivors 9.784 9.5646666 67 9.6738 1.0605328 85 0.8982353 07 0.8422392 166 10. Which results (from 5, 15, or 50 birds) do you think are closest to the means and standard deviations of the entire population of medium ground finches on the island? Explain your answer. The results from the 50-finch sample are the closest because having a larger sample size allows for a more accurate representation of the population and it increases the reliability of the findings. 11. The film that you watched before the lab that is posted on Canvas claims that beak depth is the trait that made the greatest difference in survival for the birds during the drought. Do the data you examined support this claim? Explain your answer based on your analyses and figures. Why might beak depth play a more important role in survival during the drought than either wing length or body mass? According to the data it appears that body mass and wing length had a bigger impact on survival than beak depth. However it makes sense that beak depth would play a more important role in survival because the depth of the beak could determine the ability to access and consume food sources that were available during that time. Having a larger beak depth could potentially provide an advantage in obtaining scarce resources. 4